Mr. Ercolino had worked at Hazan since 2005, according to his LinkedIn page.

WSJ: Deadly Clash Started in Workplace

Reims mayor Adeline Hazan told France's BFM television that "a very powerful explosion" had taken place, blowing out windows of nearby buildings.

NPR: 2 Die After Explosion, Building Collapse In France

Ms Hazan told BFM TV the blast - which happened at 11:15 (09:15 GMT) - had been "very strong" and had shattered windows in other buildings.

BBC: Reims blast and building collapse in France kills three

Le Web will even feature a speech from McKinsey partner Eric Hazan on how "faster than realtime" is shifting the behavior of consumption across the internet.

CNN: Should we fear mind-reading future tech?